Steady Flow of an Electrically Conducting Incompressible Viscoelastic Fluid over a Heated Plate

2005 ◽  
Vol 60 (1-2) ◽  
pp. 29-36 ◽  
Author(s):  
Mina B. Abd-el-Malek ◽  
Medhat M. Helala
Keyword(s):  
Viscoelastic Fluid ◽  
Magnetic Parameter ◽  
Transformation Group ◽  
Numerical Technique ◽  
Elastic Parameter ◽  
Heated Plate ◽  
Theoretic Approach ◽  
Electrically Conducting ◽  
Flow And Heat Transfer ◽  
Basic Equations

The transformation group theoretic approach is applied to the problem of the flow of an electrically conducting incompressible viscoelastic fluid near the forward stagnation point of a heated plate. The application of one-parameter transformation group reduces the number of independent variables, by one, and consequently the basic equations governing flow and heat transfer are reduced to a set of ordinary differential equations. These equations have been solved approximately subject to the relevant boundary conditions by employing the shooting numerical technique. The effect of the magnetic parameter M, the Prandtl number Pr and the non-dimensional elastic parameter representing the non- Newtonian character of the fluid k on velocity field, shear stress, temperature distribution and heat flux are carefully examined.

scholarly journals Impact of Different Developmental Instars on Locusta migratoria Jumping Performance

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Xiaojuan Mo ◽  
Donato Romano ◽  
Mario Milazzo ◽  
Giovanni Benelli ◽  
Wenjie Ge ◽  
...  
Keyword(s):  
High Speed ◽  
Developmental Stages ◽  
Locusta Migratoria ◽  
Biomechanical Model ◽  
Elastic Parameter ◽  
Leg Length ◽  
Jumping Performance ◽  
Locomotion Behavior ◽  
Geometrical Data ◽  
Jumping Robot

Ontogenetic locomotion research focuses on the evolution of locomotion behavior in different developmental stages of a species. Unlike vertebrates, ontogenetic locomotion in invertebrates is poorly investigated. Locusts represent an outstanding biological model to study this issue. They are hemimetabolous insects and have similar aspects and behaviors in different instars. This research is aimed at studying the jumping performance of Locusta migratoria over different developmental instars. Jumps of third instar, fourth instar, and adult L. migratoria were recorded through a high-speed camera. Data were analyzed to develop a simplified biomechanical model of the insect: the elastic joint of locust hind legs was simplified as a torsional spring located at the femur-tibiae joint as a semilunar process and based on an energetic approach involving both locomotion and geometrical data. A simplified mathematical model evaluated the performances of each tested jump. Results showed that longer hind leg length, higher elastic parameter, and longer takeoff time synergistically contribute to a greater velocity and energy storing/releasing in adult locusts, if compared to young instars; at the same time, they compensate possible decreases of the acceleration due to the mass increase. This finding also gives insights for advanced bioinspired jumping robot design.

scholarly journals Dynamic measurements of the nonlinear elastic parameter α in rock under varying conditions

2004 ◽  
Vol 109 (B2) ◽  
Author(s):  
Paul A. Johnson ◽  
Bernard Zinszner ◽  
Patrick Rasolofosaon ◽  
Frederic Cohen-Tenoudji ◽  
Koen Van Den Abeele
Keyword(s):  
Elastic Parameter ◽  
Dynamic Measurements ◽  
Nonlinear Elastic

scholarly journals Unsteady MHD Flow of a Dusty Visco-elastic Fluid between Parallel Plates with Exponentially Decaying Pressure Gradient in an Inclined Magnetic Field

2016 ◽  
Vol 8 (2) ◽  
pp. 149-157
Author(s):  
D. R. Kuiry ◽  
S. Bahadur
Keyword(s):  
Magnetic Field ◽  
Fluid Flow ◽  
Pressure Gradient ◽  
Mass Concentration ◽  
Elastic Parameter ◽  
Relaxation Parameter ◽  
Dust Particles ◽  
Physical Parameters ◽  
Time Relaxation ◽  
Elastic Fluid

The present paper deals with the unsteady laminar flow of an incompressible, electrically conducting dusty visco-elastic fluid between two parallel stationary plates. The flow is caused by an exponentially decaying pressure gradient .A uniform magnetic field is applied on the lower plate at different inclinations. We observe that the motions of the fluid and dust particles are affected by the variation of some significant physical parameters of the visco-elastic fluid. Mass concentration number, time-relaxation parameter, visco-elastic parameter, intensity of the applied magnetic field and time are some of indispensable physical parameters of fluid flow. The governing equations of motion have been solved by analytical method and the results have been discussed with the help of graphs. The velocity is observed to be symmetrical with the centre of the channel of fluid flow as well as of dust particles. The velocity of the fluid particles and that of the dust particles go on decreasing with an increase in the values of mass concentration number, magnetic field intensity, visco-elastic parameter and time whereas the velocity profiles of fluid and dust particles are observed to be increasing with an increase in the time- relaxation parameter.

scholarly journals Fluid Discrimination Based on Frequency-Dependent AVO Inversion with the Elastic Parameter Sensitivity Analysis

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Pu Wang ◽  
Jingye Li ◽  
Xiaohong Chen ◽  
Kedong Wang ◽  
Benfeng Wang
Keyword(s):  
Data Interpretation ◽  
Elastic Parameter ◽  
Pore Fluid ◽  
P Wave ◽  
Frequency Dependent ◽  
Avo Inversion ◽  
Fluid Factor ◽  
Dispersion Terms ◽  
Dispersion And Attenuation ◽  
Dispersion Term

Fluid discrimination is an extremely important part of seismic data interpretation. It plays an important role in the refined description of hydrocarbon-bearing reservoirs. The conventional AVO inversion based on Zoeppritz’s equation shows potential in lithology prediction and fluid discrimination; however, the dispersion and attenuation induced by pore fluid are not fully considered. The relationship between dispersion terms in different frequency-dependent AVO equations has not yet been discussed. Following the arguments of Chapman, the influence of pore fluid on elastic parameters is analyzed in detail. We find that the dispersion and attenuation of Russell fluid factor, Lamé parameter, and bulk modulus are more pronounced than those of P-wave modulus. The Russell fluid factor is most prominent among them. Based on frequency-dependent AVO inversion, the uniform expression of different dispersion terms of these parameters is derived. Then, incorporating the P-wave difference with the dispersion terms, we obtain new P-wave difference dispersion factors which can identify the gas-bearing reservoir location better compared with the dispersion terms. Field data application also shows that the dispersion term of Russell fluid factor is optimal in identifying fluid. However, the dispersion term of Russell fluid factor could be unsatisfactory, if the value of the weighting parameter associated with dry rock is improper. Then, this parameter is studied to propose a reasonable setting range. The results given by this paper are helpful for the fluid discrimination in hydrocarbon-bearing rocks.

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